Aug 18 2006
皇后大学researchers have devised a "green chemistry" solution to one of the oil industry's biggest problems - in a cost-effective way.
Their findings will be published in the international journal Science on Friday August 18.
The study addresses the recurring problem of separating oil and water mixtures, and targets diverse applications including cleaning up oil spills, and extracting oil deposits from tar sands and reservoirs. Other potential beneficiaries are plastics manufacturers, chemical and pharmaceutical companies, mining companies and makers of cleaning products.
The new process can be used whenever industry requires an emulsion (the mixture of two liquids in which droplets of one are suspended evenly throughout the other), explains lead researcher and Queen's Chemistry Professor Philip Jessop. This might occur when cleaning spills, extracting oil from the ground, de-greasing metal equipment or metal surfaces, and manufacturing chemical products such as plastics.
由于石油和水通常不会混合，因此必须在它们之间的层中添加“表面活性剂”（表面活性剂），然后才能创建乳液。他继续说：“问题在于，在许多情况下，您后来希望水和石油再次分离。”但是，在到目前为止已知的“可切换”表面活性剂中，一种非常昂贵，含有金属，另一种是极具毒性的，第三种是通过光激活的 - 与不透明的乳液无法很好地工作。
Old-fashioned soap can be made to "switch" but that requires large amounts of acid to be added, which is not desirable, says Dr. Jessop, Canada Research Chair in Green Chemistry. The surfactant developed by the Queen's team is also completely reversible and does not require metals, acid, or light. Exposure to carbon dioxide (CO2) activates it, while bubbling air through the liquid turns it off again. CO2 and air were chosen because they are cheap, non-toxic and environmentally benign: the CO2 can be recycled material from power plants.
"You can do this over and over, timing it for exactly when you want the switch to occur," Dr. Jessop notes. And when the surfactant is turned off, causing oil and water to separate, the now-clean water may be returned to its source or recycled.
The new surfactant builds on Dr. Jessop's discovery last year of "switchable solvents" that change their properties when alternately exposed to carbon dioxide and nitrogen, making it possible to re-use the same solvent for multiple steps in a chemical process.
杰索普博士说：“目前存在很大的分离问题，导致石油行业头痛。”“如果'绿色化学'可以解决这些问题，那么环境也会使公司在财务上受益。这是一个双赢的情况。”
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